Fig. 2. Architecture of the Banking System. C lient E nd. Server End. Server End. Server End. Server End. Graphical User Panel

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1 Distributed Banking with Mobile Agents: An Approach for E-Commerce R.B. PATEL and K. GARG Department of Electronics & Computer Engineering India Institute of Technology Roorkee, Roorkee , Uttaranchal, India Abstract: The anticipated increase in popular use of the Internet has created more opportunity in information dissemination, E-commerce, and multimedia communication. It has also created more challenges in organizing information and facilitating its efficient retrieval. From the network perspective, there are additional challenges and problems in meeting bandwidth requirement, as also in network management. In response to this, new techniques, languages and paradigms have evolved which facilitate the creation of such applications. Certainly the most promising among the new paradigms is the use of mobile agents. In this paper, mobile agent technology, as applied in an E-commerce application, is discussed. We report an implementation of a banking system, whose database may be distributed at different sites on the Internet. A customer can send his/her mobile agent to perform various tasks involved in banking and get back an appropriate result. PMADE is used as the platform to develop these mobile agents. Security checks have been also implemented, as this is an important requirement in E-commerce. Keywords: E-commerce, Mobile Agent, Distributed Database, Agent Host, Agent Submitter and PMADE. 1 Introduction Traditionally, the relationship between Providers and Customers has been specific, contractual, and largely static. The Internet, wireless and digital streaming technologies have opened up the possibilities for Providers to have as many Customers as possible and for Customers to have a choice between Providers. Together, the Internet and the Web, support growth opportunities in selling commodities, customer and service provider relationship, information searching, banking, product/service design, user support, geographic expansion, logistics, and supply chain integration. In this dynamic environment, the traditional challenge of managing a one-to-one relationship is giving way to the much greater challenge of managing many-to-one and one-to-many relationships. A user level application is an e-marketplace where vendors can set up online shops with products, services or information, for sale [1]. A commercial transaction may require real-time access to remote resources such as stock quotes, balance in accounts, current inventory, etc. For such transactions, we envision agents that embody the intentions of their creators and act and negotiate on their behalf. Mobile agent technology [2] is a very appealing solution to this kind of problem. A customer s agent would carry a shopping list along with a set of preferences, visit various sellers, get the best deal based on the preferences and purchase the product using digital forms of cash. Applications that need to monitor events on remote machines, such as, whether a particular bank account s balance has fallen below a threshold, are also benefited from mobile agents, since agents need not use the network for polling. Instead of periodically downloading bank statements, an agent can be sent to quote service to monitor the balance. The agent can inform the user when a specified event occurs. In this paper, we report on the implementation of such a banking system using mobile agent technology [3]. The mobile agent platform used is PMADE, which has been developed at IIT Roorkee itself [4, 5, 6, 7]. We are using PMADE because this platform provides mobility to agents as well as to Hosts both; other reason is that this platform can run in heterogeneous environment. The rest of the paper is organized as follows: Section 2 gives an overview of the Mobile Agent framework used for the development of application, i.e., PMADE. Section 3 discusses the architectural details of the developed banking system Section 4 gives details of the implementation of the system and the mobile agents required for this purpose. Results are discussed in section 5 and Section 6 concludes the paper. 2 Overview of PMADE Fig. 1 illustrates the detailed architecture of PMADE (A Platform for Mobile Agent Distribution and Execution) [5, 6, 7]. The Agent Host is the key component of PMADE. It consists of the manager modules and the Host Driver. The Host Driver is the basic utility module, which lies below the manager modules and is responsible for driving the Agent Host by ensuring proper co-ordination between various managers and making them work in tandem. Various manager modules form an essential part of the Agent Host. The Agent (AM) authenticates the connection with the help of (UM) and Signature (SM), as per the Agent Transfer 1

2 Protocol [4, 6] requirements. If it is able to receive the agent, it passes it to the Cloning (CM). Here, a clone of the mobile agent is created and forwarded to other Agent Hosts, if required, with the help of Address (NAM). The Host Driver summons the Agent Reply (ARM) to formulate the reply and dispatch the same to the Agent Host/Agent Submitter of the respective mobile agent. Agent Host Agents Objects Applications Signature Address Agent Cloning Host Driver Service Bridge Task Agent Submitter Resource Account Broker Agent Reply Persistence Security Agent Receiver Agent to Agent Communication (Message Queue Processor) Fig. 1. Architecture of PMADE The model also provides an in-built resource accounting feature. End-users are required to subscribe, to utilize the services of the base server (parent agent Host-where an agent is first submitted). The Resource Accounting (RAM) does this. Similarly, the Persistence (PM) is provided, so that, in case of system shutdown/breakdown, the agent state can be saved and restored for the sake of security and continuity. Provision has been also made for a Broker (BM) in the model, to facilitate brokering on the Internet. The Security (SM) provides security to Agent Host from malicious Mobile Agents as also to the static data/credential information of a Mobile Agent running on an Agent Host, from other agents running on the same host. A detailed discussion of these managers is beyond the scope of this paper, but can be seen in [4, 6]. 3 Architecture and Design of the Banking System The aspect of E-Commerce [10], on which we focus in this paper, is the payment for procurement of some commodity in any part of the world. These payments are typically done from a single account, but several alternative accounts may exist. The customer (client) dispatches one or more mobile agents, each with its list of required modes of transaction, amount and potential accounts/banks. The mobile agent visits each bank server intern to perform the required transaction. If the desired account is present, it processes the transaction on behalf of the user, else it moves to other bank servers. If the transaction is committed, or the bank list is exhausted, the mobile agent returns to the customer with the details of the operations performed. 3.1 Bank Server This is the central module of the application. All the functionality of the bank resides here. All mobile agents report to this module, which performs the actual operation (authentication & transaction) on a database and returns an appropriate message to the agent. As mentioned earlier, we have developed the banking system over PMADE. The architecture is illustrated in Fig. 2. The Bank administrator creates new accounts and has the power to check and manipulate the user s account. The customer has to go physically to the server who incorporates this program and ask to open a new account. This module has to be hooked up with the mobile agent platform. A Graphical Interface (GUI) has been designed. The administrator uses the services of the following: New-Account module: This module helps to create an account & check and update its information. It returns a Credit Card ID and Account Holder Signature for every new account. Credit Card ID is automatically generated by the database. Account Holder Signature is generated using Hashing Algorithms (SHA-1 or MD5) and signed with DSA for checking tampering. Balance module accepts the Credit Card ID and Account Holder Signature of an existing account and returns the balance in that account from the Balance Book. The entire procedure takes place via a form. A GUI has also been provided so that a customer, who has failed to submit a mobile agent, can himself/herself do a transaction. Credit and Debit modules: These modules perform the actual credit/debit into the account. All the above modules display appropriate messages after each operation, informing either successful transaction execution or stating reasons for failure. A GUI, with a Help facility, has been designed for ease of use of these modules. 2

3 The Bank Server has two stationary agents called the Credit Stationary Agent and Debit Stationary Agent, which provide second level security to the bank account is opened in the bank. It is searched by either Credit Card ID or by Account Holder Signature fields. Both can be considered as primary keys to this table Graphical Panel C lient E nd To Agent Submitter Interface PM ADE Server Bank Server System Administrator Bank Database Fig. 2. Architecture of the Banking System database after the authentication by PMADE itself. A mobile agent uses the services of these modules to perform the required transactions by furnishing the required parameters to them. Mobile agents do not themselves fetch, search or update the bank database. This is done for enhancing the security of the system and prevents an authorized customer from creating a malicious agent who can manipulate his/her account. The stationary agents perform the actual transaction and inform the mobile agents whether the transaction was successfully completed or reasons for its failure. 3.2 Distributed Database A distributed database [11] is required to hold all the data pertaining to the banking system, like details of customers, transactions completed, accounts, etc. It may be distributed by fragmentation, or replication, or both. The designed application supports all three types of distributed databases and uses a relational database model. All the updates are made in parallel in all parts of the database. Once a database is opened by an entity (mobile agent), no one else can access it (for updates, but reading is permissible) until this entity has released the database. Thus at any time, the database is under control of only one mobile agent. This feature supports concurrency control in the database. Deadlocks are avoided by making all operations independent of others and having a single control on the database. No cyclic dependency occurs and no roll back is required. The mobile agent may be terminated if it stays for a long period on the server or it may itself migrate to another server if it does not get access to the databases. The following tables are used in the database: Ledger Book: which contains information about every account holder. An entry is made in it whenever a new separately. These are generated automatically by the Bank Administrator whenever a new entry is made. A Mobile agent is checked for authentication by these fields before it is forwarded for further operation. Balance Book: has an entry for each account holder and contains information about the present balance in it. It is searched and updated by its two fields jointly, i.e., Credit Card ID and Account Holder Signature, each one is primary key to this table. It is updated whenever a transaction takes place, after authentication from the Ledger Book. Credit and Debit Books: Credit and Debit books are used to generate reports of all the transactions that the customer has made. An entry is made for every credit/debit transaction here. It is important to note that the database is opened in read only mode, since an agent may be required to find only the balance in an account. For e.g., a seller wanting to check if a potential customer has sufficient funds or not. 4 Implementation The application is developed in JAVA 2 version 1.2. PMADE is used as the mobile agent platform. All programming is done in Windows 9x/NT environment. (a) Design of Database: The database is made in MS Access 97 and the driver used to run this database is Microsoft Access Driver of ODBC (Object Database Connectivity). JAVA has its own database driver called JDBC (Java Database Connectivity). The interface between these two has been provided by JDBC-ODBC Protocol. All queries are made in SQL (Structured Query Language). 3

4 (b) Integration with the PMADE: s can interact with PMADE by developing agent application programs. In PMADE infrastructure, agent application programs are implemented as Java objects. s would first need to write a Java class that specifies some action, such as accessing a database on a remote node. Once this Java class is written and compiled, the user can launch the agent program in three ways: (1) via a GUI Agent Launch Wizard, (2) via a command line tool, or (3) using the external API (Agent Programming Interface). The first two mechanisms are provided with PMADE, while the last one requires the user to write a customized launch class, which makes use of the PMADE class libraries. (c) Mobile Agents A single agent is sufficient for performing the same task on different banks. When the agent reaches an Agent Host, it makes clones of itself and sends them to all the places where a bank server is running. Hence all the databases, where the customers account exists, are updated simultaneously, allowing concurrent execution. This feature makes handling of a distributed database possible. Three mobile agents are used in the Banking System. Every mobile agent implements Agent abstract class, this class provides property to an agent by which PMADE recognize it. The agent BFindAgent gets the balance in the customer s account. It carries information (customer name, customer ID and customer signature) about the Customer, for accessing its account. Agent AgentDebit debits from customer s account. When it reaches the agent host, it calls the AuthenticatorDebit stationary agent, which provides the actual operation to be performed on the database. It carries the information: customer name, customer ID, customer signature and amount. Similarly agent AgentCredit credits into a customer s account. When it reaches the agent host it calls the AuthenticatorCredit stationary agent which facilitates for performing actual operation on the database. It carries the information: customer name, customer ID, customer signature, Cheque/DD/No, Cheque/DD Date, Paying bank name and amount on the cheque/dd. user of this host is accepted. Due to this reason, propagation and authentication time is large in this case, because an acknowledgement information is required to be sent to the host (agent launcher host). This model is used when a customer/supplier wants to check the current balance in the account of a customer who wants to purchase/deliver some commodity from/to supplier/customer. It does not increase traffic on the network as only a single copy of the agent travels on the network. Table 1. Single agent migrating from node to node on Started from Agent Submitter Departed at Returned at Server IP Arrival to start processing database to leave database to depart Propagation/ Authentication Case 2: Parallel operation by cloned agents. Table 2 shows the movement of agent from an agent submitter to the parent agent host (this is host where the agent was first submitted). PMADE authentication (first level security) is done at this host only as it is treated as the master node for creating and controlling the clones. After authentication at the parent host, clones of the agent are created and launched to remote agent hosts. These clones work in parallel and after completion of the task at remote agent hosts, they are required to report at the parent host. When all the clones have returned to the parent host, the Cloning compiles the result and sends it to the Agent Reply, from where it reaches the agent launcher. This table shows a propagation/ authentication time of , which is very small in comparison to , of Table 1. Table 2 shows the cloned agent working at the database at the same time, i.e., the database is updated in parallel, as mentioned in section 3.2. This model is used for credit and debit operations. Table 2. Clones of an agent working in parallel on different nodes on Started from Agent Submitter Departed at Return at Server IP Arrival to start processing database to leave database to depart Propagation/ Authentication Discussion of Results We have tested our banking system on a 4-node network for two cases results of which are shown by Tables 1 and 2. Case 1: Serial itinerary with PMADE authentication [12, 13, 14, 15] at every host. Table 1 shows the movement of an agent from node to node. We have launched an agent and provided it a set of Agent Hosts ( nodes) where it has to do work. The agent is authenticated by PMADE at every host before accepting it. The agent comes from a client who is an authorized Note: is represented as hh:min:sec:millsec. We have tested on small amounts of data. When data is large, propagation and authentication time may be considered negligible. Both the cases can be used for finding customers account balance information or for credit/debit in the customer s account. 6 Conclusion This paper has reported on the implementation and results of a banking system based on mobile agents. 4

5 Security of the system from mobile agents has been incorporated at two levels. At the first level we authenticate mobile agents at the Agent Host. This is done by PMADE At the second level, the customer is authenticated by the stationary agents. The banking system has been implemented and tested over the Internet in the laboratory. In this paper we have reported only the Banking System part of an E-commerce system. Currently we are in the process of implementing a buyers/suppliers system. Agents are dispatched by the buyer to various suppliers, where they negotiate orders and deliveries, returning to the buyer with their best deals for approval. It is possible to have a deep supply chain, where a supplier may need to contact further suppliers of sub components in order to respond to an entry. Further, the application designed here is based on the pull model, in which the client s mobile agent visits the bank server. A different system, based on the push model, in which the bank s mobile agent regularly visits the client, is also being tried. Performance improves in this case as security checks can be bypassed. Also the bank can regularly advertise new schemes. It can also warn a client when he/she is low on credit (balance) etc, using its own agents. This is under consideration. References [1] Prithaviraj Dasgupta, Nitya Narasimhan, Louse E.Moser, MAgNET: Mobile Agents for ed Electronics Trading, IEEE Transaction On knowledge and data engineering, vol. 11, no. 4, July/Aug [2] Menelaos K. Perdikeas Fotis Chatzipapadopoulos and Lakovos S. Venieris, An Evaluation Study of mobile agent Technology: Standardization, Implementation and Evolution, IEEE, 1999, /99, pp [3] Agrawal, N., A Distributed Banking System Using Mobile Agents: An Approach for E-commerce, Masters Thesis Department of Electronics & Computer Engineering, IIT Roorkee, India, Feb [4] Patel, R.B. and Garg, K. A Mobile Agent Framework for Parallel & Distributed Computing (PMADE), A Technical Report [5] Patel R.B. and Garg Kumkum, PMADE A Platform for mobile agent Distribution & Execution, in the Proceedings of 5 th World MultiConference on Systemics, Cybernetics and Informatics (SCI2001) and 7 th International Conference on Information System Analysis and Synthesis (ISAS 2001), Orlando, Florida, USA, July 22-25, 2001, Vol. IV, pp [6] Patel R.B. and Garg Kumkum, Mobile Agent Management in PMADE, in Proceeding of ADCOM 2001, 9 th International conference on Advanced Computing and Communications, Bhubaneshwar, India, Dec , [7] Patel, R.B. and Garg, K., Communication Mechanisms for mobile agents, in Proceedings of First International ICSC Congress on AUTONOMOUS INTELLIGENT SYSTEMS, Deakin University Waterfront Campus, Geelong Australia, Feb , [8] Fünfrocken S., Migration of Java-based Mobile Agents - Capturing and Reestablishing the State of Java Programs, MA 98: Proceedings 2nd International Workshop on Mobile Agents, [9] Hyacinth S. Nwana Software Agents: An Overview, Knowledge Engineering Review, Vol. 11, No. 3, pp. 1-40, Sept. 1996, Cambridge University Press, [10] Azarmi Nader, Thint Marcus and Ohtani Takeshi, Enhancing E-Communities with Agent-Based Systems, IEEE Computer, pp , July [11] Jonathan Dale, A Mobile Agent Architecture for Distributed Information Management, Ph.D. thesis, 1997, [12] Wayne Jansen and Tom Karygiannis, NIST Special Publication Mobile Agent Security National Institute of Standards and Technology, Computer Security Division, Gaithersburg, MD [13] Nayeem Islam, et al., A Flexible Security System for Using Internet Content, IEEE Software, Sept. 1997, pp [14] Patel, R.B. and Garg, K., A Security Framework for Mobile Agent Systems, in Proceedings of 6 th International Conference on Business Information Systems (BIS 2003), Colorado, Spring, USA, June 4-6, 2003, pp [15] Patel, R.B. and Garg, K., Providing Security and Robustness to Mobile Agents on Open s, in Proceedings of 6 th International Conference on Business Information Systems (BIS 2003), Colorado, Spring, USA, June 4-6, 2003, pp (Received, Best Paper Award). 5